(1) Field of the Invention
The present invention relates to the transmission and reception of digitalized multimedia content data on a network such as a home network.
(2) Description of the Related Art
In recent years, digital broadcasting such as BS digital broadcasting, CS 110-degree digital broadcasting, and digital terrestrial broadcasting has commenced. Furthermore, DVR for recording a TV-program in a recording medium for digital data such as a Hard Disk Drive (HDD), a Blu-Ray Disc (BD), and a Digital Versatile Disc (DVD) is becoming popular. With this, digitalized multimedia content that can be used in households is increasing.
Meanwhile, with the development of the broadband environment, internet access from households is becoming widespread. Accordingly, the spread of the so-called home network, in which the respective rooms in a house are connected by an IP network, is also advancing.
With such a situation, digital broadcasts received by a digital broadcast receiver in the house, or digital contents stored in a recorder can now be viewed at other rooms, using the home network.
With regard to such sharing of digital content using a home network, there is a move to make this possible not only between the above-mentioned CE devices, but also between all devices connected to a home network, including personal computers (PC) and Personal Digital Assistants (PDA). To be more specific, standardization organizations such as the Digital Living Network Alliance (DLNA) have laid-out and made public standards and implementing guidelines for this purpose.
In such content sharing, the method defined in the UPnP AV Architecture is widely used in the recognition of the devices and the exchange of information on the contents that can be used, between a server (for example, a set top box or DVR which receives digital broadcasts) and a client (for example, a personal computer or a digital player) in the home network. In UPnP AV, upon receiving an inquiry from the client, the server replies with a list of provided contents and the attributes of each of the contents. Furthermore, as a mandatory protocol for transmission of content data, Hypertext Transfer Protocol (HTTP) is used in DLNA.
In such sharing of content in a home network, for example, in the case of sharing a broadcast content among plural terminals using the network, it is necessary to follow a broadcast standard such as the ARIB Standard in Japan or the DVB Standard in Europe. In these standards, when outputting to a network, it is stipulated that the output format must be the Partial TS format. Furthermore, in a broadcast, version up of section data, which carries structure information within a stream and/or application information, notifies an update of information inside of the stream. In order to obtain such update information, it is necessary for the client to receive and analyze all the Partial TS on the server over the network.
However, when reproducing a recorded content via the network, it does not follow that the client necessarily receives all the data of the Partial TS of the content. For example, when the client carries out trick play of the content existing on the server, the client can use a method for selectively receiving and reproducing certain sections of the content. At this time, when there is an update-point such as a change of the structure in the stream and/or version up of section data, and the like, problems occur, such as not being able to correctly reproduce the stream and/or not being able to activate an application of the data broadcast.